1. Field of the Invention
The present invention relates to a method for processing a large number of fish eggs, in particular to an automated method for processing fertilized fish eggs. The invention can be employed for production method of producing genetically recombinant proteins and so on from fertilized fish eggs by gene injection. Moreover, the invention can be employed to produce materials by means of using fertilized fish eggs.
2. Description of the Related Art
A method to produce specific protein is known by injecting gene material to the fertilized egg of the fish. This protein-producing method may have high productivity, because the specific fish such as the zebra fish lay eggs approximately every day.
The gene material must be injected into each fish eggs before dividing of a cell of the fertilized fish egg is started. However, a very large number of the fish eggs employed for the gene-injection is very small. For example, the eggs of the zebra fish have a diameter of about 1 mm. It is not easy to deal very large number of small fish eggs within a short time. Moreover, the injection apparatus for injecting the gene material into the small fish egg is expensive, because precision control is required for an injection needle to inject the gene material into the very small fish egg.
Japan Unexamined Patent Publication No. 2007/222,132 proposes an egg-arranging plate for arranging fish eggs. A large number of concave portions are formed on a top surface of the egg-arranging plate. Each bottom of concave portions has each drainage aperture with a narrow path for draining water. Each one of fish eggs must be caught in each one of concave portion by the water passing through the concave portion. However, the fish egg dropped in the concave portion is easy to leave the concave portion by moving of the water or the egg-arranging plate.
The Publication No. 2007/222,132 proposes the concave portion having a narrow aperture to prevent that the fish egg in the concave portion leaves the concave portion too. However, it becomes difficult for the fish egg to drop into the concave portion, too. Moreover, the fish egg has damage, because a negative pressure of the concave portion must be increased for absorbing the fish egg.
Nextly, dropping the fish eggs into almost of the concave portions needs long time. Furthermore, remaining of the fish egg on the egg-arranging plate causes an error of gene-injection. Moreover, inserting of a needle for injecting gene materials is not easy, because the fish egg is very small and easy to be moved by forcing of the needle.
U.S. Patent Application Publication No. 2008/0077329A1 proposes to prevent the moving of the fish egg by means of absorbing the fish egg with the negative pressure of the concave portion. However, the fish egg must be absorbed by the small holes strongly. As the result, the fish egg may have damage.